Methods for manufacturing micromechanical components and method for manufacturing a mould insert component

ABSTRACT

Method of manufacturing a micromechanical component intended to cooperate with another micromechanical component, the method comprising the steps of providing a substrate, forming a mould on said substrate, said mould defining sidewalls arranged to delimit said micromechanical component, providing particles on at least said sidewalls, depositing a metal in said mould so as to form said micromechanical component, and liberating said micromechanical component from said mould and removing said particles.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. application Ser. No.16/431,073, filed Jun. 4, 2019, which claims priority to EuropeanApplication No. 18175930.9, filed Jun. 5, 2018, the entire contents ofwhich are incorporated herein by reference.

TECHNICAL FIELD

The present invention relates to the technical field of micromechanics.More particularly, it relates to methods of manufacturingmicromechanical components and to a method of manufacturing a mouldinsert component for the manufacture of a micromechanical component.

STATE OF THE ART

Micromechanical components, such as horological components, MEMScomponents and so on, are often required to interact kinematically witheach other by frictional contact.

Such components, which may for instance be gear wheels, levers, cams andso on, typically have dimensions of the order of several hundred micronsof thickness, and diameters or lengths ranging from several millimetresto several centimetres. Due to the extremely small size of suchcomponents, predetermined surface finishes are required for tribologicalreasons. The typical approach for such finishing is to first manufacturethe components, and then subject them to a surface treatment such aspolishing, roughening or similar, as required depending on theproperties needed.

However, more advanced surface finishes are often desirable so as tooptimise friction and/or handling of lubricants by optimising thewetting of the surface.

These surface finishes can be applied to the components e.g. by laserablation, trowalisation, plasma treatment, dry or wet etching etc., withor without a mask.

For finishing treatments such as trowalisation or dry-wet etchingwithout a mask, the surface structures obtained have well definedlength-scales but have random shapes with non-optimal tribologicalproperties. Other techniques such as anodization lead to better definedsurface structures but are limited to specific materials (e.g. aluminiumor titanium etc.). Laser ablation can be used to fabricate well definedsurface structures at the sub-microscale but is limited in terms ofthroughput and feasibility when processing complex 3D microparts.

In another process, it is known to deposit an adhesion layer on theotherwise-completed component, upon which micro- or nano-particles canbe deposited. A subsequent mask inversion and etching step createshollows in the surface.

Although they allow the surface structuring of sidewalls of parts, suchprocesses are time-consuming and are carried out on otherwise completecomponents, adding process steps to their manufacture and requiringhandling of otherwise-finished components. The sidewalls are the areasof the components which are typically subject to friction, particularlyin the case of gearwheels and similar, and it is thus highly desirableto be able to influence their properties for tribological andlubrication-related reasons during their formation rather than as extrasteps.

An aim of the present invention is thus to at least partially overcomethe above-mentioned drawbacks of the prior art.

DISCLOSURE OF THE INVENTION

According to a first aspect, the invention relates to a method ofmanufacturing a micromechanical component intended to interact withanother micromechanical component via a frictional contact, such as ahorological component or a MEMS component, more specifically e.g. a gearwheel, a lever, a cam, a rack, an anchor, a ratchet, a jumper spring, asliding component, a clutch, a cam follower, a mainspring housing orsimilar with predefined, well-defined surface structures on theirsidewalls. This method comprises the steps of:

providing a substrate, e.g. made of silicon or other suitable material;

forming a mould directly or indirectly on said substrate, said moulddefining sidewalls delimiting said micromechanical component, i.e.defining its shape. Photostructurable SU-8 polymer is a non-limitingexample of a material suitable for such a mould, and is well-known inthe context of the LIGA process; alternatives can be thermal nanoimprintor UV-nanoimprint (also referred as UV-casting);

providing particles on said mould, namely on at least said sidewallsthereof, either by depositing already-formed particles thereupon or byforming/growing said particles in situ;

depositing a metal such as nickel, phosphor bronze, nickel-phosphor,brass, copper or other suitable metal in said mould so as to form saidmicromechanical component, e.g. by electroforming or by electrolessplating as appropriate;

liberating said micromechanical component from said mould and removingsaid particles in the same step or in a subsequent step.

It should be noted that extra intermediate steps are not excluded bythis method, or by any other method of the invention.

As a result, it is possible to structure the sidewalls of the componentin a controlled fashion, with surface cavities defined in function ofthe type and size of said particles, in a simple step during manufactureof the component rather than in a post-formation step requiringcomplicated handling and extra processing. This permits optimisation ofthe tribological properties of the sidewalls of the component, andretention of lubricant (if applicable) during manufacture and withoutfurther finishing being required.

According to a second aspect, the invention relates to a method ofmanufacturing a mould insert component intended for the manufacture of amicromechanical component intended to interact with anothermicromechanical component via a frictional contact, e.g. of the typesmentioned above. This method comprises the steps of:

providing a substrate made e.g. of silicon or another suitable material;

forming a mould on said substrate, said mould defining sidewallsdelimiting the shape of said mould insert. Photostructurable SU-8polymer is a non-limiting example of a material suitable for such amould, and is well-known in the context of the LIGA process;

providing particles on at least said sidewalls, either by depositingalready-formed particles thereupon or by forming them in-situ;

depositing a metal in said mould so as to form said mould insertcomponent, said metal being e.g. nickel, phosphor bronze,nickel-phosphor, brass, copper or other suitable metal e.g. byelectroforming or by electroless plating as appropriate;

liberating said mould insert component from said mould and removing saidparticles.

The sidewalls of the mould insert component are thus structured asdescribed above, this structure being transferred to a finalmicromechanical component formed by using a moulding tool provided withthe mould insert (see below), thus enabling the final component to havestructured sidewalls as described above.

Advantageously, in either aspect of the invention, the particles mayhave at least one dimension ranging from 1 nm to 10 μm, preferably from10 nm to 8 μm, further preferably from 50 nm to 5 μm, and can bedeposited in a single layer or in two or more layers so as to form ahierarchical structure or a porous surface. In the case of two or morelayers, each layer may comprise particles having either similardimensions to make a porous surface or substantially differentdimensions to make a hierarchical structured surface. In the case ofhierarchical structures, the particles of one layer having preferably atleast twice the diameter of those of the other layer, further preferablyat least five times said diameter, even further preferably at least tentimes said diameter.

Advantageously, a further step of depositing an adhesion layer at leaston said sidewalls prior to providing said particles can be performed, soas to improve the adhesion of the particles on the sidewalls of themould.

Advantageously, the particles can also be deposited directly orindirectly upon said substrate, which prevents any masking of thesubstrate from being necessary to selectively deposit particles only onthe sidewalls.

Advantageously, the methods can further comprise a step of removingexcess metal prior to liberating the component or said mould insertcomponent from said mould, as is the case.

The particles may comprise e.g. at least one organic material such asmelamine, polyimide, polysulfone, polystyrene, polystyrenesulfonic acid,polystyrene sulfonate, polyacrylate, or polymethylmetacrylate;copolymers (incl. block-, graft and star-copolymer) such as particlesmade of polystyrene-polymethylmetacrylate; polystyrene-polyvinylpyrine,polystyrene-polyethyleneoxide and/or inorganic substances such astitanium oxide, silicon oxide, aluminium oxide, zinc oxide, or nickeloxide. In the case of multiple layers of particles, each layer maycomprise the same or different particles, and the particles may behybrids comprising both inorganic and organic components, and/ordifferent types of particles in the same layer.

The particles can be deposited by a wet deposition technique such asimmersion coating, spray coating, spin coating or dip coating.

A third aspect of the invention relates to a method of manufacturing amicromechanical component intended to interact with anothermicromechanical component via a frictional contact, the methodcomprising the steps of:

manufacturing a moulding tool comprising a mould insert component asdefined above, said mould insert component at least partially definingthe shape of the micromechanical component;

depositing material (such as metal, bulk metallic glass, polymer,ceramic or similar) into said moulding tool by any convenient process soas to form said micromechanical component;

liberating said micromechanical component from said moulding tool.

This method likewise results in the structure of the particles beingtransferred to the final micromechanical component as discussed above,since the surface-structured mould insert component serves to define atleast partially the shape of the micromechanical component.

In another variant, the method of manufacturing a micromechanicalcomponent intended to interact with another micromechanical componentvia a frictional contact, the method comprising the steps of:

forming a moulding tool comprising a mould insert component as mentionedabove;

depositing material into said moulding tool so as to form a furthermould insert component;

liberating said further mould insert component from said moulding tool;

forming a further moulding tool comprising said further mould insertcomponent;

depositing material into said further moulding tool so as to form saidmicromechanical component;

liberating said micromechanical component from said further mouldingtool.

This enables, for instance, mass production of the final components bymeans of a sacrificial further mould insert manufactured with the helpof a durable mould insert.

The material used to fill the moulding tool or the further moulding toolmay be polymer, metal, bulk metallic glass, ceramic, diamond-likecarbon, or a combination of materials. As a result, the sidewallstructuring can be applied to micromechanical components made of anymouldable material.

Advantageously, the moulding tool is an injection moulding toolcomprising a cavity defined at least partially by said mould insert, andwherein said material is deposited by injection moulding of moltenpolymer into said cavity.

The invention also relates to a micromechanical component obtainableand/or obtained by one of the above-mentioned methods, as well as to amould insert component obtainable and/or obtained by the correspondingmethods mentioned above.

It should be noted that the various features of the methods can becombined in any way which makes technical sense.

BRIEF DESCRIPTION OF THE DRAWINGS

Further details of the invention will appear more clearly upon readingthe description below, in connection with the following figures whichillustrate:

FIG. 1 illustrates schematically a first embodiment of a method ofmanufacturing a micromechanical component according to the invention;

FIG. 2 illustrates schematically and partially a second embodiment of amethod of manufacturing a micromechanical component according to theinvention;

FIG. 3 illustrates schematically a method of manufacturing a mouldinsert component and of manufacturing a micromechanical component or afurther mould insert component according to a method of the invention;and

FIG. 4 illustrates schematically steps subsequent to those of FIG. 3 inrespect of a further method of manufacturing a micromechanical componentaccording to the invention on the basis of said further mould insert.

FIGS. 5a-d are electron micrographs at various resolutions illustratingresults obtained with the method of the invention.

EMBODIMENTS OF THE INVENTION

FIG. 1 illustrates a first embodiment of a method of manufacturing amicromechanical component 13 according to a method of the invention,said micromechanical component being intended to cooperate with anothermicromechanical component (which may or may not itself be made accordingto the invention) via a frictional contact, this frictional contactbeing either static and/or dynamic. This component 13 may be ahorological or MEMS component, and may for instance be a gear wheel, arack, a ratchet, a lever, a cam, a mainspring housing, a jumper spring,an anchor, a clutch, a sliding component, or any other componentintended to interact with another via a frictional contact. This contactis typically via the sidewalls of the component 13, these sidewallsjoining two faces of the component which each define a plane and whichare typically parallel with each other. In other words, the sidewalls donot themselves meet in a sharp point, but rather join with a plane whichis at an angle thereto. Typically, the component has a minimum dimensionof 0.1 mm considered in this plane, and is hence not a needle-typestructure, but is rather a component defining a plane. Themicromechanical component 13 may be intended for a horologicalapplication, a MEMS application, or any other micromechanicalapplication. To this end, MEMS is defined as micromechanical systemsmanufacturable by micromachining technology such as LIGA, etching and soon.

In step 101, a substrate 1 is provided. This is typically made ofsilicon, which can be monocrystalline, polycrystalline, or amorphous, orcan be another substance such as a metal, silicon oxide, siliconnitride, silicon carbide or similar. It can also be e.g. siliconprovided with surface layer of another material. Substrate 1 may beflat, or may be curved or otherwise structured.

In step 102, a mould 3 is formed on the substrate 1, e.g. by depositionand selective removal of material. Typically, the mould 3 is of SU-8epoxy resin or other negative-type resins (although positive-type resinsare also possible), which is selectively photostructured by means of amask or by direct laser exposure, the unexposed portions being removedby an appropriate solvent. However, other similar processes are known inthe art, such as direct laser ablation of mask material. The mould 3thus obtained comprises sidewalls 5 which delimit the sidewalls of thecomponent 13 when this latter has been formed. In the variantillustrated in FIG. 1, these sidewalls 5 are substantially perpendicularto the substrate 1. However, they can also be angled, for instance so asto produce a conical gear, or other micromechanical component comprisingangled sidewalls.

In step 103, an adhesion layer 7 is deposited on the mould 3 (includingits sidewalls 5) and the exposed parts of the substrate 1. This adhesionlayer 7 promotes the adhesion of particles 9 in step 104, and is anoptional step in the case in which adhesion of the particles 9 directlywith the mould 3 is adequate. In this latter case, the adhesion layer 7illustrated in the figures should be deemed to be absent.

The adhesion layer can for instance comprise a molecular film ofbifunctional molecules having a high affinity for the surface of themould 3 (their first functionality) and for the particles coated on thesurface (their second functionality). Examples of such substances arefunctional silanes having amine functionality, thiols having acarboxylic acid, amine, phosphonic acid, amide, trimethylammoniumbromide functionality, sulfonates having amine, thiol, carboxylic acid,phosphonic acid, amide, phosphonates having a carboxylic acid, amine,phosphonic acid, amide, trimethylammonium bromide and more generallyrandom or block-copolymers. Alternatively, linear, branched or dendriticmacromolecules with functional groups having a high affinity for boththe surface of the mould and the particles can be used. Examples of suchsubstances are PAMAM (Poly(amidoamine)), polyethylene imine, polystyrenesulfonate, polyacrylic acid, polydiallyldimethylammonium chloride, andpolylysine. Alternatively, metal salts such as polyaluminium chloridecan be used or functional silsesquioxanes. A yet further possibility isa thin film of metal oxide such as AlOx, SiOx, or TiOx. A yet furtherpossibility for the prime layer is a dual layer formed of combinationsof two layers of the examples given above with for instance a layer ofmetal oxide and a bifunctional molecule or a linear, branched ordendritic macromolecule.

Depending on the substance chosen for the adhesion layer, it can bedeposited either by wet deposition techniques such as immersion coating,spray coating, spin coating, and dip coating, or by vacuum depositiontechniques such as atomic layer deposition, molecular vapor depositionand so on.

In step 104, particles 9 of a size preferably ranging from 1 nm to 10μm, further preferably from 10 nm to 8 μm, even further preferably from50 nm to 5 μm, are provided on the adhesion layer 7 or directly on themould 3 and substrate 1 if the adhesion layer 7 is not used. It shouldalso be noted that it is possible, although difficult, to mask theexposed parts of the substrate 1 such that the particles 9 are onlyprovided on the sidewalls 5 and the upper surface of the mould materialand not on the exposed parts of the substrate 1 or of the adhesion layer7 situated thereupon. Particles 9 may be substantially spherical,cylindrical, rods, polyhedral (prisms, cubes, cuboids, octahedra,pyramids, tetrahedra and so on), or may be of irregular form. In suchcases, the size ranges given above refer to their major (i.e. longest)dimension.

These particles 9 may comprise organic materials such as melamine,polyimide, polysulfone, polystyrene, polystyrenesulfonic acid,polystyrene sulfonate, polyacrylate, polymethylmetacrylate, or similar.The particles could also comprise at least two types of monomer orpolymer subunits as found in copolymers (incl. block-, graft andstar-copolymer) such as particles made ofpolystyrene-polymethylmetacrylate; polystyrene-polyvinylpyrine,polystyrene-polyethyleneoxide. The particles could also be inorganicsubstances such as titanium oxide, silicon oxide, aluminium oxide, zincoxide, nickel oxide or similar. Alternatively, they can be hybridcomposite particles comprising both organic and inorganic components.The particles 9 are typically provided on the surfaces in question bybeing deposited thereupon as already-formed particles, which may e.g. bedeposited by wet deposition techniques including immersion coating,spray coating, spin coating, dip coating and similar.

Other processes are possible in which the particles 9 are formed insitu, such as vacuum deposition techniques including chemical vapordeposition (CVD), atomic layer deposition (ALD) which allow thedeposition of conformal coatings with specific growth mode (dewetting ofthe growing material, nucleation and growth). As reported by Puurrunenet al “Formation of Metal Oxide Particles in Atomic Layer DepositionDuring the Chemisorption of Metal Chlorides: A Review” Chem. Vap.Deposition, 2005, 11: 79-90, the ALD process can be used for thefabrication of metal oxide nanoparticles. Fenollosa et al reported in“Porous silicon microspheres: synthesis, characterization andapplication to photonic microcavities” J. Mat. Chem. 20, 5210-5214(2010) that submicron silicon particles can be produced by CVD. Anotherpossible process for the deposition of particles is the combination ofthin film deposition and sintering processes. Coatings deposited byvacuum techniques (e.g. ALD, CVD, PVD, evaporation techniques orsimilar) have been combined with an annealing step to induce dewettingof a thin film of particle precursor and formation of droplets whichform the particles 9. This process has been used for photovoltaics andhas been used for the fabrication of light trapping layers (Krishna etal, Nanotechnology, Volume 21, Issue 15, article id. 155601, 7 pp.(2010)).

Subsequently, in step 105 the mould 3 is filled with metal 11 forinstance by electrolytic deposition or by electroless (autocatalytic)deposition so as to form the component 13 in the mould 3. One face ofthe component 13 is defined by the substrate 1. Such depositionprocesses are extremely well-known in the art, particularly in thecontext of the LIGA process, and do not need to be discussed in detailhere. Suitable metals are nickel, brass, copper, phosphor bronze, nickelphosphor and many other metals used for micromechanical components andwhich can be deposited in bulk.

In step 106, excess metal 11 a is removed by mechanical polishing,leaving the component 13 in the mould 3.

Finally, in step 107, the component 13 is removed from the mould, theparticles 9 being removed at the same time or subsequently, for instanceby mechanical, solvents, acidic or basic solutions and/or plasma removalof the mould 3 together with any adhesion layer 7. The complete removalof the mould and particles 9 may be achieved in a single step dependingon the materials of the particles or in a two steps process to removesequentially the mould and the particles. The resulting componenttypically has a thickness of between 100 μm and 3 mm, and dimensionsperpendicular to said thickness of the order of 10 μm to 20 mm.preferably from 100 μm to 10 mm

It can clearly be seen that the sidewalls 13 a of the component aretextured, having taken on the negative form of the sidewalls 5 of themould 3 and the particles 9 previously deposited thereupon, theseparticles 9 each having left a corresponding cavity 15 in the component13. It should thus be clear that the surface finish of the sidewalls 13a of the component 13 can be varied by varying the size, density anddistribution of particles 9 during their deposition in step 104.

FIG. 2 illustrates this principle applied to step 104 of the method, inwhich several layers of particles 9 are deposited or formed in-situ onthe adhesion layer 7 (or directly on the mould 3 and substrate 1 if noadhesion layer is present). The particles 9 of each layer may have thesame or similar diameters, or may be different sizes. For instance,larger particles 9 may be deposited or formed in contact with theadhesion layer 7 with smaller particles deposited or formed thereupon soas to provide a hierarchical texture to the finished component 13, withsmaller cavities provided inside larger ones. In such a case, theparticles 9 provided directly on the adhesion layer 7 may have adiameter at least 5 or 10 times larger than that of the smallerparticles 9 provided thereupon, preferably around 10 times larger (i.e.from 8 to 12 times larger) to have a sufficient particle density,

Steps 105 to 107 follow as before, with the double textured structure ofthe component 13 being clearly visible as indicated in step 107, thecavities 15 taking the negative shape of the multiple layers ofparticles 9.

FIG. 3 illustrates a method according to the invention of manufacturinga mould for a micromechanical component, as well as manufacturing thefinal component 13.

Steps 201 to 206 correspond to steps 101 to 106 of FIG. 1 and need notbe re-described, except in reference to the following differences.

Instead of defining the micromechanical component 13 directly, the mould3 is shaped so as to form a mould insert component 12 intended to beintegrated into a moulding tool (such as an injection moulding tool) forproducing the final component 13 by moulding after the mould insertcomponent 12 has been liberated from the mould 3. As such, the mouldinsert component 12 serves to define at least part of the cavity in amoulding tool which defines the shape of the component 13. In theillustrated embodiment, this mould insert component intended to bemounted in an injection moulding tool (not illustrated), but other typesof moulding tools (hot embossing, UV-casting, sintering,electrodeposition, electroless deposition and so on) are also possible.As a result, the mould 3 substantially conforms to the shape of thefinal component 13, since this method is a positive-negative-positiveprocess. Since the sidewalls of the mould insert component 12 aretextured, they should be arranged so as to form a taper sufficient topermit extraction of the component 13 without damage from the mouldformed using the mould insert component 12.

Hence, steps 201 to 206 define a method of manufacturing a mould insertcomponent 12 for the manufacture of a micromechanical component 13, andsubsequent steps 207 and 208 complete the manufacture of the component13.

In step 207, the mould insert component 12 has been mounted in amoulding tool, such as an injection moulding tool, so as to define acavity delimiting the micromechanical component 13, and material 17 hasbeen deposited therein. In the case of injection moulding, this materialis molten polymer material or UV-curable resin which has been injectedtherein so as to form the component 13. This material is then allowed tosolidify. Other types of moulding tools are also possible, and thematerial 17 may be deposited by sintering, electroforming, electrolessdeposition, CVD, PVD, ALD or any other method which is suitable inrespect of the material chosen. This material can e.g. be polymer,metal, bulk metallic glass, ceramic, diamond-like carbon, or similar,suitable for the deposition process chosen.

In step 208, the component 13 is removed from the mould. The component13 as illustrated may for instance be an interior conical gear such asmay be used in a spherical differential gear. To form exterior gears,the shape of the initial mould 3 can be adjusted as required.

The method of FIG. 3 can also be modified such that the component 13 asillustrated therein is in fact a further mould insert component 12 awhich is then subsequently mounted in a further moulding tool used toproduce the component 13 in the two further steps illustrated in FIG. 4.The further mould insert component 12 a thus forms part or the entiretyof a further mould forming a cavity defining the shape of the finalcomponent 13. This results in a negative-positive-negative-positiveprocess, in which each of these stages comprises respectively the mould3, the first mould comprising the mould insert component 12, a furthermould comprising the further mould insert component 12 a, and the finalcomponent 13.

In step 209, this further moulding tool is filled with material 19, e.g.by injection moulding, sintering, electroforming, electrolessdeposition, CVD, PVD, ALD or any other method which is suitable inrespect of the material chosen. This material can e.g. be polymer,metal, ceramic, diamond-like carbon, or similar.

In step 210, the final component 13 is liberated from the further mould.If the mould defined using the further mould insert component 12 a isoverfilled (as is the case in step 105 of FIG. 1), a step ofmechanically removing excess material as in step 106 can also beperformed.

The further mould insert component 12 a may be durable if it is made ofa relatively hard material such as metal, ceramic, or similar or may besacrificial if it is made of polymer or other soft material. In fact,this longer process is particularly useful in the case in which themould insert component 12 is durable (e.g. made of metal, ceramic orsimilar wear-resistant material) and the further mould insert component12 a is sacrificial, since many further mould insert components 12 a canbe inexpensively fabricated by means of the mould insert component 12,which only needs to be produced in small numbers.

FIGS. 5a-d are electron micrographs of a side surface of a horologicalanchor manufactured by a method according to the invention, at variousmagnifications. FIG. 5b is corresponds to the area inside the blackrectangle of FIG. 5a , FIG. 5c corresponds to the area inside the blackrectangle of FIG. 5b , and FIG. 5d corresponds to the area inside theblack rectangle of FIG. 5c .

In this test, a silicon wafer (thickness: 1 mm, orientation: (111))constituting the substrate 1 was coated with gold. After applying a 200μm coating of SU-8 photoresist, a photolithography step was carried outto form a mould 3 delimiting the lateral dimensions of the parts to beproduced and the sidewalls of these parts. The surface of the SU-8coated substrate 1 was activated using a barrel oxygen plasma. A layerof polyethylene imine (constituting adhesion layer 7) was deposited onthe SU-8 in a conformal way by immersion coating. Polystyrene particles9 were then deposited in a conformal way on the all of the mould 3,sidewalls 5 included, by immersion coating. The surface of the SU-8mould 3 coated with adhesion layer 7 and particles 9 was activated usinga barrel oxygen plasma. A 200 μm layer of nickel 11 was thenelectroplated in the mould using a nickel sulfamate bath so as to formthe part 13.

After liberation from the mould 3 and removal of the particles withtoluene, the part 13 was placed under an electron microscope to obtainthe images of its sidewall reproduced here, these images clearly showingthe cavities 15, each with a diameter of around 0.5 μm, caused by thepresence of the particles 9 in the mould 3. These cavities provide atexture to the sidewall surface.

Although the invention has been described in terms of specificembodiments, variations thereto are possible without departing from thescope of the invention as defined by the appended claims.

The invention claimed is:
 1. A method of manufacturing a micromechanical component intended to interact with another micromechanical component via a frictional contact, comprising the steps of: providing a substrate; subsequently forming a mould on said substrate, said mould defining sidewalls arranged to delimit said micromechanical component; subsequently providing particles on at least said sidewalls; subsequently depositing a metal in said mould so as to form said micromechanical component; subsequently liberating said micromechanical component from said mould and removing said particles.
 2. The method according to claim 1, wherein said particles have at least one dimension ranging from 1 nm to 10 μm.
 3. The method according to claim 2, wherein said particles are provided in at least two layers, each layer comprising particles having substantially different dimensions, the particles of one layer having at least twice the diameter of those of the other layer.
 4. The method according to claim 2, wherein said particles are provided in at least two layers, each layer comprising particles having substantially the same diameter.
 5. The method according to claim 1, wherein said particles are also provided upon said substrate.
 6. The method according to claim 1, wherein said particles comprise at least one organic material selected from melamine, polyimide, polysulfone, polystyrene, polystyrenesulfonic acid, polystyrene sulfonate, polyacrylate, polymethylmetacrylate, polystyrene-polymethylmetacrylate copolymer, polystyrene-polyvinylpyrine polymer, or polystyrene-polyethyleneoxide copolymer; and/or inorganic substances selected from titanium oxide, silicon oxide, aluminium oxide, zinc oxide, or nickel oxide.
 7. The method according to claim 1, wherein said particles are provided by deposition, comprising depositing particles by a wet deposition technique selected from immersion coating, spray coating, spin coating or dip coating.
 8. The method according to claim 1, wherein said particles are provided by being formed in situ, by one of chemical vapour deposition, atomic layer deposition, or physical vapour deposition.
 9. A method of manufacturing a mould insert component adapted for the manufacture of a micromechanical component by moulding, said micromechanical component being intended to cooperate with another micromechanical component via frictional contact, said method comprising the steps of: providing a substrate; subsequently forming a mould on said substrate, said mould defining sidewalls arranged to delimit said mould insert; subsequently providing particles on at least said sidewalls; subsequently depositing a metal in said mould so as to form said mould insert component; subsequently liberating said mould insert component from said mould and removing said particles.
 10. The method according to claim 9, wherein said particles have at least one dimension ranging from 1 nm to 10 μm.
 11. The method according to claim 10, wherein said particles are provided in at least two layers, each layer comprising particles having substantially different dimensions, the particles of one layer having at least twice the diameter of those of the other layer.
 12. The method according to claim 10, wherein said particles are provided in at least two layers, each layer comprising particles having substantially the same diameter.
 13. The method according to claim 9, wherein said particles are also provided upon said substrate.
 14. The method according to claim 9, wherein said particles comprise at least one organic material selected from melamine, polyimide, polysulfone, polystyrene, polystyrenesulfonic acid, polystyrene sulfonate, polyacrylate, polymethylmetacrylate, polystyrene-polymethylmetacrylate copolymer, polystyrene-polyvinylpyrine copolymer, or polystyrene-polyethyleneoxide copolymer; and/or inorganic substances selected from titanium oxide, silicon oxide, aluminium oxide, zinc oxide, or nickel oxide.
 15. The method according to claim 9, wherein said particles are provided by deposition, by depositing particles by a wet deposition technique selected from immersion coating, spray coating, spin coating or dip coating.
 16. The method according to claim 9, wherein said particles are provided by being formed in situ, by one of chemical vapour deposition, atomic layer deposition, or physical vapour deposition.
 17. A method of manufacturing a micromechanical component intended to interact with another micromechanical component via a frictional contact, the method comprising the steps of: forming a moulding tool comprising a mould insert component according to the method of claim 9; depositing material into said moulding tool so as to form said micromechanical component; liberating said micromechanical component from said moulding tool.
 18. The method according to claim 17, wherein said material comprises at least one of be polymer, metal, ceramic, or diamond-like carbon.
 19. The method according to claim 17, wherein said moulding tool is an injection moulding tool comprising a cavity defined at least partially by said mould insert, and wherein said material is deposited by injection moulding of molten polymer into said cavity.
 20. A method of manufacturing a micromechanical component intended to interact with another micromechanical component via a frictional contact, the method comprising the steps of: forming a moulding tool comprising a mould insert component according to the method of claim 9; depositing material into said moulding tool so as to form a further mould insert component; liberating said further mould insert component from said moulding tool; forming a further moulding tool comprising said further mould insert component; depositing material into said further moulding tool so as to form said micromechanical component; and liberating said micromechanical component from said further moulding tool.
 21. The method according to claim 20, wherein said material comprises at least one of be polymer, metal, ceramic, or diamond-like carbon.
 22. The method according to claim 20, wherein said further moulding tool is an injection moulding tool comprising a cavity defined at least partially by said mould insert, and wherein said material is deposited by injection moulding of molten polymer into said cavity. 